Non-spill container with flow control structure including baffle and elastic membrane having normally-closed pinholes

ABSTRACT

A flow control structure for a non-spill beverage container that includes a tube-like spout defining a flow channel, and a substantially flat membrane supported by the spout over one end of the flow channel, and an annular baffle mounted in the flow channel. The membrane punctured to form multiple, substantially round pinholes arranged in a two-dimensional pattern that remain closed to prevent fluid and air flow under normal atmospheric conditions, and open and to facilitate fluid flow rate through the membrane under an applied pressure differential (e.g., when sucked on by a child). The annular baffle defines an opening that limits differential pressures applied to the membrane when not in use, thereby acting in combination with the membrane to prevent leaks. The baffle opening is also sized such that, during normal use (e.g., sucked on by a child), substantial flow is generated through the membrane.

FIELD OF THE INVENTION

The present invention relates to fluid flow control devices for non-spill beverage containers, and more specifically it relates to “no drip” flow control structures for, e.g., child sippy cups and adult “travel” mugs.

RELATED ART

Sippy cups and travel mugs represent two types of non-spill beverage containers that utilize flow control devices to control the ingestion of beverage in response to an applied sucking force. Sippy cups are a type of spill-resistant container typically made for children that include a cup body and a screw-on or snap-on lid having a drinking spout molded thereon. An inexpensive flow control element, such as a soft rubber or silicone outlet valve, is often provided on the sippy cup lid to control the flow of liquid through the drinking spout and to prevent leakage when the sippy cup is tipped over when not in use. Adult non-spill “travel” mugs are usually fabricated from a thermally insulating material, and have a narrow spout that restricts flow of a hot beverage (e.g., coffee). A valve similar to that used on child sippy cups is sometimes incorporated into such travel mugs to prevent spills.

“No drip” sippy cup flow control valves typically include a sheet of the elastomeric material located between the inner cup chamber and the open end of the drinking spout that defines one or more slits formed in an X or Y pattern. As a child tilts the container and sucks liquid through the drinking spout, the slits yield and the flaps thereof bend outward, thereby permitting the passage of liquid to the child. When the child stops sucking, the resilience of the causes the slits to close once more so that were the cup to be tipped over or to fall on the floor, liquid cannot pass out of the container through the drinking spout.

One problem associated with conventional non-spill cups is that the elastomeric material used to form the slit-type “no drip” flow control valves can fatigue in the region of the slits and/or become obstructed over time, and the resulting loss of resilience can cause leakage when the slit flaps fail to fully close after use. This failure of the slit flaps to close can be caused by any of several mechanisms, or a combination thereof. First, repeated shearing forces exerted at the end of each slit due to repeated use can cause tearing of the elastomeric material in this region, thereby reducing the resilient forces needed to close the slit flaps after use. Second, thermal cycling or mechanical cleaning (brushing) of the elastomeric material due, for example, to repeated washing, can cause the elastomeric material to become less elastic (i.e., more brittle), which can also reduce the resilience of the slit flaps. Third, solid deposits left by liquids passing through the slits can accumulate over time to impede the slit flaps from closing fully.

A second problem associated with conventional non-spill cups is that the “no drip” flow control valves are typically located inside the short, straw-like drinking spout such that a small, open upper section of the spout is located above the valve. During each sip, liquid is drawn through the valve (which is pulled open by the applied suction), and the passes through the open upper section of the drinking spout into the drinker's mouth. Because the valve closes at the end of each sip (i.e., when the applied suction is terminated), a small amount of liquid is typically “trapped” (retained) in the upper section (i.e., between the now-closed valve and the open end of the drinking spout). Because the upper end of the drinking spout is open to the air, this small amount of liquid can drip or be shaken from the end of the drinking spout and create, for example spots on a light colored carpet.

What is needed is a flow control structure for non-spill sippy cups and travel mugs that exhibits superior non-spill, no-drip characteristics. What is also needed is a flow control structure that automatically adjusts its fluid flow rate to the applied suction, and avoids the clogging and tearing problems associated with conventional slit-type elastic flow control structures. What is also needed is a non-spill beverage container that omits the small, open upper section of the drinking spout.

SUMMARY

The present invention is directed to a flow control structure for a non-spill beverage container (e.g., a child sippy cup or an adult travel mug) that includes a tube-like spout defining a relatively wide flow channel, a membrane extending across an end of the flow channel, and a baffle supported in the flow channel that provides a small opening between a beverage storage chamber and the membrane. The membrane is formed from a suitable elastomeric material (e.g., soft rubber, thermoplastic elastomer, or silicone) that is punctured to form multiple, substantially round pinholes that remain closed to prevent fluid flow through the membrane and flow channel under normal atmospheric conditions (i.e., while the membrane remains non-deformed), thereby providing a desired “no drip” characteristic. The baffle further enhances this “no drip” characteristic by acting to limit fluid pressure in the region between the baffle and the membrane (i.e., in the presence of a higher fluid pressure downstream of the baffle). Conversely, when subjected to such an applied pressure differential (e.g., when sucked on by a child), the membrane stretches (deforms), thereby causing some or all of the pinholes to open and to facilitate fluid flow rate through the membrane, which is substantially unimpeded by the baffle under these conditions. Because the amount that the pinholes open, and the associated fluid flow through the pinholes, is related to the applied pressure differential, the present invention provides a flow control structure that automatically adjusts its fluid flow rate to the applied suction. In addition, because the pinholes are substantially round, the pinholes resist the clogging and tearing problems associated with slit-type flow control structures.

According to another embodiment of the present invention, a non-spill beverage container includes a container body, a cap mounted over an open end of the container body, and a flow control structure mounted on the cap such that a spout of the flow control structure extends through an opening in the cap. The flow control structure includes an outer, relatively flexible member that includes a tube-like outer spout portion and the membrane, and an inner, relatively rigid member that includes the baffle. The inner member includes a base that is screwed, snap-coupled or otherwise secured to the cap, and an inner spout portion that forms the flow channel. The outer member mounts over the inner spout portion such that the membrane is positioned at the upper end of the spout. Because the membrane is located at the end of the spout, when a user finishes drinking and the pinholes close, beverage that may be retained in the flow channel is prevented from dripping from the spout by the membrane, thus avoiding the dripping problem associated with conventional non-spill beverage containers.

The present invention will be more fully understood in view of the following description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective side view showing a flow control structure according to a generalized embodiment of the present invention;

FIGS. 2(A) and 2(B) are top and cross-sectional side views, respectively, showing the flow control structure of FIG. 1;

FIGS. 3(A) and 3(B) are simplified diagrams illustrating tensile forces generated in flat and curved membranes;

FIGS. 4(A) and 4(B) are simplified enlarged cross-sectional views showing the opening of a pinhole formed in the flow control element of FIG. 2 during operation;

FIGS. 5(A) and 5(B) are cross-sectional side views showing the flow control structure of FIG. 1 during operation.

FIG. 6 a cross-sectional side view showing a non-spill beverage container including a flow control structure according to an exemplary embodiment of the present invention;

FIGS. 7(A) and 7(B) are cross-sectional side and plan views showing an inner portion of the flow control structure utilized in the non-spill beverage container of FIG. 6;

FIGS. 8(A) and 8(B) are cross-sectional side views showing a process of assembling the flow control structure of FIG. 6 in accordance with another aspect of the present invention;

FIG. 9 is a top plan view showing a cap of the non-spill beverage container of FIG. 6;

FIGS. 10(A) and 10(B) are cross-sectional side views showing a process for mounting the flow control structure of FIG. 8(B) onto the cap of FIG. 9 according to another aspect of the present invention;

FIG. 11 is a top plan view showing a process for securing the flow control element of FIG. 8(B) to the cap of FIG. 9(B);

FIGS. 12(A) and 12(B) are cross-sectional side views showing the non-spill beverage container of FIG. 6 during operation;

FIG. 13 is a perspective side view showing a non-spill beverage container including a flow control structure according to another exemplary embodiment of the present invention; and

FIGS. 14(A) and 14(B) are cross-sectional side views showing a process for mounting the flow control structure onto the cap of the non-spill beverage container of FIG. 13 according to another aspect of the present invention.

DETAILED DESCRIPTION

FIG. 1 is a perspective view showing a flow control structure 40 according to a generalized embodiment of the present invention, and FIGS. 2(A) and 2(B) show flow control structure 40 in top plan and cross-sectional side views, respectively, where FIG. 2(B) is taken along section line 2-2 of FIG. 2(A).

Flow control structure 40 includes a molded (first) member 50 including a tube-like spout 54 defining a substantially cylindrical flow channel 56, a membrane 55 mounted on an upper (first) end 54A of spout 54, and a baffle 65 mounted inside flow channel 56 between upper end 54A and a lower end 54B of spout 54. Spout 54 is a relatively rigid (i.e., compared to membrane 55) tube-like structure extending generally along a central axis X between upper end 54A and lower end 54B of spout 54. As indicated in FIG. 2(A), in one embodiment spout 54 has a circular cross section having an inner diameter (width) D1. In other embodiments, spout 54 may have, for example, an oval, square or rectangular cross section.

Membrane 55 is relatively elastic (i.e., compared to spout 54) and is connected to spout 54 adjacent to (i.e., at or slightly inset from) upper end 54A such that membrane 55 is disposed across fluid flow channel 56 to impede flow from fluid flow channel 56 and an external region ER. In the disclosed embodiment, membrane 55 has a circular outer perimeter 57 that is secured to upper end 54A of spout 54. In one embodiment, elastic membrane 55 is formed from a suitable material (e.g., soft rubber, thermoplastic elastomer, or silicone) having a thickness T1 in the range of 0.01 to 0.1 inches (more particularly 0.01 to 0.03 inches), and spout 54 is formed from the same material and has a thickness T2 in the range of 0.05 to 0.12 inches. According to the present invention, membrane 55 defines a plurality of spaced-apart pinholes 59 formed using the procedure describe below such that when membrane 55 is subjected to normal atmospheric conditions (i.e., remains non-deformed), pinholes 59 remain closed to prevent fluid flow between fluid flow channel 56 and external region ER through membrane 55. As described in additional detail below, pinholes 59 are also formed such that when membrane 55 is deformed (stretched) in response to an applied pressure differential between fluid flow channel 56 and external region ER, pinholes 59 open to facilitate fluid flow through membrane 55. Accordingly, pinholes 59 facilitate adjustable fluid flow through membrane 55 that increases in direct relation to the applied pressure differential, thereby facilitating the formation of a non-spill beverage container.

As indicated in FIG. 2(B), according to an embodiment of the present invention, membrane 55 is substantially flat (planar) in its relaxed (i.e., non-deformed or unstretched) state, and lies in a plane X-Y that is perpendicular to central axis X of flow channel 56. Two advantages are provided by making membrane 55 in this manner. A first advantage, which is illustrated by the simplified diagrams shown in FIGS. 3(A) and 3(B), is that a flat membrane is easier to stretch under an applied pressure than a curved membrane. In particular, as depicted in FIG. 3(A), a pressure P_(Z) applied perpendicular to substantially flat membrane 55 causes membrane 55 stretches (bows downward, as indicated by the dashed membrane 55′). Note that because membrane 55 is substantially flat, virtually all of the resultant tensile force T generated in membrane 55 is directed in the X-Y plane (indicated by component T_(X-Y)), thereby generating little or no component T_(Z) in the Z-axis direction until the membrane is at least partially stretched. Because the tension component T_(Z) remains relatively small, planar membrane 55 is stretched (and the pinholes opened) in response to a relatively small applied pressure P_(Z), thereby facilitating fluid flow through membrane 55 in response to a relatively small sucking force. In contrast, as indicated in FIG. 3(B), a pre-curved membrane 310 generates a significantly larger tensile force component T_(Z), thereby requiring a substantially larger pressure P_(Z) to produce even a minimal stretching of membrane 310 from its resting position (e.g., as indicated by deformed membrane 310′, shown in FIG. 3(B)). A second advantage to provided by making membrane 55 substantially flat is that, as described below, formation of the pinholes is greatly simplified and facilitated.

Although the preferred embodiment includes a substantially flat (planar) membrane, a curved membrane may also be used, although such membrane would necessarily be relatively thin (i.e., relative to a flat membrane formed from the same material) in order to facilitate a similar amount of deformation in response to an applied pressure. A problem posed by using a relatively thin membrane is the increased chance of rupture and/or tearing of the membrane material, which may result in the unintended ingestion of membrane material.

Referring to FIG. 2(A), according to an aspect of the present invention, membrane 55 defines a plurality of spaced-apart pinholes 59 that are arranged in a two-dimensional pattern. The term “spaced-apart” is used to indicate that the pinholes are separated by regions of non-perforated membrane material (i.e., there are no holes, cracks, slits, or other significant structural weaknesses in the membrane material in the regions separating adjacent pinholes). The spacing between pinholes 59 is selected based on the membrane material such that tearing of the membrane material between adjacent pinholes is avoided under normal operating conditions (i.e., the pinholes are spaced as far apart as is practical). Note that arranging pinholes 59 in a two-dimensional pattern provides the advantage of balancing the distribution of forces across membrane 55, thereby reducing the chance of tearing of the membrane material.

According to an aspect of the present invention, spout 54 has a greater rigidity than the membrane 55 such that, when an applied pressure differential is generated between fluid flow channel 56 and external region ER, membrane 55 undergoes a greater amount of deformation than spout 54. In one embodiment, membrane 55 and spout 54 are integrally connected to form an single-piece member 50, which is molded from a suitable material (i.e., both spout 54 and elastic membrane 55 are molded in the same molding structure using a single molding material, e.g., silicone, a thermoplastic elastomer, or soft rubber), and the increased rigidity is provided by forming spout 54 to include a thickness T1 that is greater than the thickness T2 of membrane 55. In an alternative embodiment, spout 54 may be formed at least partially from a relatively rigid material (e.g., a hard plastic), and membrane 55 may be separately formed from a relatively elastic material and then secured to wall member 54. One example of this arrangement is described below with reference to the disclosed specific embodiment.

Referring again to FIGS. 1 and 2(A), membrane 55 is depicted as being secured around its peripheral edge 57 to upper end 54A of spout 54. Alternatively, membrane 55 may be recessed into flow channel 56 to avoid damage caused, for example, by gumming or chewing on the end of flow control structure 40, provided membrane 55 is positioned between baffle 65 and external region ER. However, significantly recessing membrane 55 creates an open upper region between the end of flow channel 56 (i.e., upper end 54A of straw-like spout 54) that may undesirably create a reservoir for small amounts of liquid that can drip after each sip, as described above with respect to conventional non-spill beverage containers.

In accordance with another aspect of the present invention, several pinholes 59 are formed in membrane 55 to facilitate liquid flow from flow channel 56 to external region ER in response to an applied pressure differential (e.g., an applied suction). As indicated in FIG. 4(A), each pinhole 59 is formed by piercing membrane 55 with a pin 410, or other sharp pointed object, such that the pinhole is closed by the surrounding elastomeric material when pin 400 is subsequently removed. In a preferred embodiment, membrane 55 is stretched in a radial direction by a force F that is sufficient to increase the diameter of membrane 55 in the range of 1 to 10 percent during the formation of pinholes 59. When the stretching force F is subsequently removed (i.e., membrane 55 returns to an unstretched state), pinholes 59 are collapsed by the surrounding membrane material to provide a reliable seal. In accordance with another aspect, each pin 410 is formed with a continuously curved (e.g., circular) cross section such that each pinhole 59 is substantially circular (i.e., does not have a slit or fold that would be formed by a cutting element having an edge). In one embodiment, pin 410 has a diameter in the range of 0.020 and 0.065 inches. Note that a pin having a diameter DIA of approximately 0.063 inches was used in a punch (8 mm depth on press) to produce successful pinholes in a membrane having a thickness of approximately 0.02 inches. The number of pinholes 59 and membrane thickness T3 determine the amount of liquid flow through membrane 55 during use for a given pressure differential, as discussed below. During operation, as described in additional detail below, membrane 55 is positioned between a liquid beverage (not shown) and an external region. While atmospheric equilibrium is maintained (i.e., the pressure on both sides of membrane 55 is essentially equal), membrane 55 remains in the unstretched state illustrated in FIG. 4(A), wherein pinholes 157 remain closed to prevent leakage. During subsequent use (e.g., when a child sucks on spout 54 like a straw), a pressure differential is generated in which a relatively high pressure on the liquid side of membrane 55 becomes greater than the relatively low pressure on the suction side, thereby causing membrane 55 to stretch outward, as indicated in FIG. 4(B). The stretching of membrane 55 causes pinholes 59 to open, thereby allowing the liquid beverage to pass therethrough. Subsequently, when the pressure differential is relieved (i.e., the child stops sucking), membrane 55 then returns to its unstretched state, and pinholes 59 return to the closed state shown in FIG. 4(A). Note that because pinholes 59 do not include slits that can become weakened and/or trap deposits that can prevent slit flap closure, the flow control structure of the present invention facilitates leak-free operation that is substantially more reliable than that of conventional, slit-based flow control members.

Baffle 65 is an annular structure located inside flow channel 56 and spaced from membrane 55 such that an upper (first) flow channel region 56A is defined between baffle 65 and membrane 55, and a lower (second) flow channel region 56B is located on a side of baffle 65 that is opposite to membrane 55 (e.g., between baffle 65 and a beverage reservoir). Flow channel regions 56A and 56B communicate through opening 67, which has a relatively small diameter D2 (FIG. 2(A)). In one embodiment, baffle 65 is a substantially disk-shaped structure that is parallel to membrane 55 (when in its substantially planar, unstretched state), and opening 67 is aligned with the central axis X defined by spout 54. In alternative embodiments baffle 65 is either integrally connected to spout 54 and membrane 55 (i.e., formed as part of first member 50, as depicted in FIG. 2(B)), or fabricated separately from a second material (e.g., a rigid plastic), and inserted into flow channel 56, such as described below with reference to the disclosed specific embodiment.

FIGS. 5(A) and 5(B) are cross-sectional side views showing a simplified beverage container 500 including flow control structure 40 during operation. Beverage container 500 includes a container body 510 having an outer wall 511 defining a beverage storage chamber 517 containing a liquid beverage BVG, and an opening 519. Flow control structure 40 is mounted over open end 519 such that flow channel section 56B communicates directly with chamber 517 via open end 519, and baffle 65 is positioned between chamber 517 and flow channel section 56A. FIG. 5(A) shows beverage container 500 in an inverted position prior to use (i.e., such that atmospheric pressure is applied to the outside surface of membrane 55, and beverage BVG is prevented from leaking out of container 500 solely by flow control structure 40), and FIG. 5(B) shows beverage container 500 while a suction is applied to flow control structure 40 by an external body 530 (e.g., a child's mouth). In one embodiment, as indicated in FIG. 5(B), spout 54 and baffle 65 respectively have a greater rigidity than membrane 55 such that, when the applied pressure differential is generated between fluid flow channel 56 and external region ER (e.g., inside external body 530), membrane 55 undergoes a greater deformation than spout 54 and baffle 65 in order to, for example, prevent collapse of flow control element 40 during use.

According to another aspect of the present invention, baffle 65 and membrane 55 combine to further enhance the no-drip/non-spill characteristic of flow control structure 40. First, the inventor discovered that providing baffle 65 in flow channel 56 limits the static pressure transmitted to membrane 55 while container 500 is held in the inverted position indicated in FIG. 5(A). More specifically, the inventor discovered that placing baffle 65 into flow channel 56 allowed the inventor to increase the flow rate characteristics of membrane 55 (e.g., reduce the thickness of membrane 55 and/or increase the size of pinholes 59), making membrane 55 more suitable for high volume flow, without increasing the tendency for membrane 55 to leak in the inverted position. The inventor currently believes that this beneficial characteristic may be produced, at least in part, by a combination of baffle 65 acting to limit the static pressure transferred to flow channel region 56A from chamber 517, and by surface tension of beverage BVG in and around opening 67. A second benefit of baffle 65 is that it impedes relatively high pressure spikes in flow channel region 56A that are generated, for example, when beverage container 500 is shaken up and down or dropped while in the inverted position shown in FIG. 5(A). The inventors discovered that, when combined with a membrane that exhibits leakage in response to such pressure spikes in the absence of baffle 65, the presence of baffle 65 significantly reduced and/or eliminated leakage through membrane 55, even when an associated beverage container is shaken vigorously. As a third benefit, referring to FIG. 5(B), when subsequently subjected to suction by external body 530, the relatively high static pressure differential creates liquid flow through membrane 55 that appears to be minimally impeded by baffle 65. Accordingly, the inventor found that by combining the increased flow rate characteristics of membrane 55 with baffle 65, flow control structure 40 provides superior non-spill, no-drip characteristics, compared to conventional non-spill designs. Further, membrane 55 operates as described above to automatically adjust the fluid flow rate through flow control structure 40 to the applied suction, and to avoid the clogging and tearing problems associated with conventional slit-type elastic flow control structures.

The present invention will now be described with reference to a specific embodiment.

FIG. 6 is a side view showing a non-spill beverage container 600 that utilizes a flow control structure 640 formed in accordance with another specific embodiment of the present invention. Container 600 generally includes a hollow cup-shaped body 610, and a cap 620 having flow control structure 640 mounted thereon. Body 610 includes a roughly cylindrical sidewall 611 having a threaded upper edge 613, and a bottom wall 615 located at a lower edge of sidewall 611. Sidewall 611 and bottom wall 615 define a beverage storage chamber 617 in which a beverage is received during use. Cap 620 includes a base portion 622 having threaded inside surface that mates with threaded upper edge 613 to connect cap 620 to body 610, and an upper wall 625 mounted on an upper edge of base portion 622 that combines with body 610 to substantially enclose storage chamber 617. Upper wall 625 defines an outlet passage 626 and a vent hole 627. Provided at a lower surface of upper wall 625 is a cylindrical mounting structure 629 to which flow control structure 640 is secured. Note that cylindrical mounting structure 629 surrounds outlet passage 626 and vent hole 627.

According to the specific embodiment, flow control structure 640 includes an outer (first) member 650 that is mounted over an inner (second) member 660. Outer member 650 is molded from a relatively flexible elastomeric material (e.g., soft rubber, thermoplastic elastomer, or silicone), and inner member 660 is molded from a relatively rigid, food-safe plastic material (e.g., polypropylene). Outer member 650 includes a disk-shaped base 652 defining a vent structure 653, a tube-like outer spout portion 654 connected at its lower end 654B to base 652 and extending upward at an angle from base 652, and a membrane 655 mounted across an upper end 654A of outer spout portion 654. Vent structure 653 is a domed protrusion that extends downward from disk-shaped base 652, and includes a slit (not shown) that, similar to conventional valve structures, opens in response to relatively low air pressure inside beverage chamber 617 caused by beverage being drawn (sucked) through flow control structure 640. Inner member 660, which is shown in additional detail in FIGS. 7(A) and 7(B), includes a disk-shaped base 662 that defines a vent hole 663 and includes a thread 662T formed on its peripheral edge, a tube-like inner spout portion 664 extending upward at an angle from base 662 and defining an oval flow channel 666 having a minimum width W1 and a maximum width W2, and a baffle 665 mounted in spout 664 between an upper end 664A and a lower end 664B. As in the general embodiment described above, flow channel 666 is separated into two regions 666A and 666B by baffle 665, with lower flow channel region 666B communicating with beverage storage chamber 617. In one embodiment, disk-shaped base has a diameter D11 of approximately one inch, oval passage has a width W2 of approximately 0.4, respectively, and opening 667 formed in baffle 665 has a diameter D12 of approximately 0.01 to 0.1 inches. Note that disk-shaped base 652 has a diameter that is slightly smaller than diameter D11.

FIGS. 8(A) and 8(B) are cross-sectional side views showing a process of assembling flow control structure 640. FIG. 8(A) shows outer member 650 positioned over inner member 660 such that upper end 664A of inner spout portion 664 is positioned for insertion into an opening 656 defined by outer spout portion 654. Valve member 650 is then pressed over spout 654 until a lower surface of base 652 rests on an upper surface of base 662, and membrane 655 presses against upper end 664A of inner spout portion 664, with slit-like vent extending through vent opening 663. As indicated in FIG. 8(B), membrane 655 defines several normally-closed pin-holes 659 that are formed and function as described above with reference to pin-holes 59.

FIG. 9 is a top plan view showing cap 620 in additional detail. Outlet passage 626 is a curved opening that extends partially around the circumference of cylindrical mounting structure 629 (indicated with dashed lines), which extents from the bottom side of wall 625. Vent hole 627 is also located inside the circumference of cylindrical mounting structure 629.

FIGS. 10(A), 10(B) and 11 depict a process for mounting flow control structure 640 onto cap 620. As shown in FIG. 10(A), flow control structure 640 is positioned below wall 625 of cap 620 such that membrane 655 is positioned under outlet passage 626. Flow control structure 640 is then pushed upward such that spout 654/664 passes through outlet passage 626 until threads 662T formed on the outer edge of disk-shaped base 662 engage matching threads formed on the inside surface of cylindrical mounting structure 629. As indicated in FIG. 11, with spout 654/664 protruding from upper wall 625 and positioned at the leftmost edge of outlet passage 626 (indicated by dashed line structure 640A), flow control structure 640 is then screwed/secured onto cylindrical mounting structure 629 by manipulating (sliding) spout 654/664 along outlet passage 626 to its rightmost edge (as indicated by solid line structure 640B), thus causing threads 662T of disk-shaped base 662 to screw into cylindrical mounting structure 629 and to press base 652 against the lower surface of wall 625, thus providing a reliable seal. Note that, when flow control structure 640 is in the “locked” position (i.e., represented by solid line structure 640B in FIG. 11), vent hole 627 aligns with vent structure 653 (as indicated in FIG. 10(B)) thereby facilitating pressure equalization during use.

FIGS. 12(A) and 12(B) are cross-sectional side views showing the non-spill beverage container 600 when at least partially filled with a liquid beverage BVG). FIG. 12(A) shows non-spill beverage container 600 in a tipped position whereby beverage BVG is able to flow to membrane 655 by way of lower flow channel region 666B, opening 667 formed in baffle 665, and upper flow channel region 666A. As described above with reference to the generalized embodiment, baffle 665 and membrane 655 combine to prevent leakage when a user is not applying suction to the end of spout 654/664. When suction is applied by a user (not shown), the applied pressure differential causes membrane 655 to bend outward to open pinholes 659 in the manner described above. As beverage BVG is drawn by the user through spout 654/664, the resulting vacuum generated in storage chamber 617 is equalized by way of vent hole 627 and vent structure 653.

In accordance with another benefit of the present invention, as indicated in FIG. 12(B), because membrane 655 is located at the end of spout 654/664, when a user finishes drinking and membrane 655 closes, beverage that may be retained in upper flow channel region 656A is prevented from dripping or otherwise discharging from spout 654/664, thus avoiding the dripping problem associated with conventional non-spill beverage containers.

FIG. 13 is a perspective side view showing a non-spill beverage container 700 in accordance with another specific embodiment of the present invention. Container 700 generally includes a hollow cup-shaped body 710, and a cap 720 having flow control structure 740 mounted thereon. Similar to the previous embodiment, body 710 is a cup-shaped structure including a roughly cylindrical sidewall having a threaded upper edge.

As shown in FIGS. 14(A) and 14(B), cap 720 includes a base portion 722 having a threaded surface that mates with body 710, and an upper wall 725 mounted on an upper edge of base portion 722 that combines with body 710 to substantially enclose a beverage storage chamber. Upper wall 725 defines an outlet passage 726 and a vent hole (not shown). Provided at a lower surface of upper wall 725 around outlet passage 726 is a cylindrical mounting structure (wall) 729, which includes a lip structure 729L formed on an inside surface of cylindrical mounting structure 729 to which flow control structure 740 is secured as described below.

Flow control structure 740, which is also shown in FIGS. 13 and 14, includes an outer (first) member 750 that is mounted over an inner (second) member 760. Outer member 750 is molded from a relatively flexible elastomeric material (e.g., soft rubber, thermoplastic elastomer, or silicone), and inner member 760 is molded from a relatively rigid, food-safe plastic material. Outer member 750 includes a disk-shaped base 752 defining a vent structure (not shown), a tube-like outer spout portion 754 connected at its lower end to base 752 and extending upward from base 752, and a membrane 755 mounted across an upper end of outer spout portion 754. Inner member 760 includes a disk-shaped base 762 that defines a vent hole (not shown), a tube-like inner spout portion 764 extending upward from base 762 and defining a flow channel 766, and a baffle 765 mounted between an upper end and a lower end of spout 764. As in the general embodiment described above, flow channel 766 is separated into two regions by baffle 765, with the lower flow channel region communicating with the beverage storage chamber (not shown).

FIGS. 14(A) and 14(B) illustrate a process for mounting flow control structure 740 onto cap 720. As shown in FIG. 14(A), flow control structure 740 is positioned below wall 725 of cap 720 such that membrane 755 is positioned under outlet passage 726. Flow control structure 740 is then pushed upward (i.e., in the direction of the dashed-line arrow) such that spout 754/764 passes through outlet passage 726 until the peripheral edge of disk-shaped base 762 engages (i.e., is snap-coupled to) lip structure 729L formed on the inside surface of cylindrical mounting structure 729, as indicated in FIG. 14(B). An advantage of this embodiment is that it avoids the need to turn (screw) flow control structure 740 relative to cap 720, thereby simplifying the mounting procedure and eliminating the elongated groove needed in the previous embodiment.

In addition to the general and specific embodiments disclosed herein, other features and aspects may be added to the novel flow control structures that fall within the spirit and scope of the present invention. For example, outer members 650/750 of flow control structures 640/740 (described above) may omit base 652/752, and instead rely on another mechanism to secure membranes 655/755 to inner spout portion 664/764. The disclosed single-hole baffle structure may be replaced with a multi-holed baffle, or any baffle structure that defines at least one opening for permitting fluid flow, but limits dynamic pressure changes in the flow channel in the manner described herein. In addition, the disclosed cylindrical mounting structures may be a shape other than cylindrical, and base 662/762 may be removably attached to the mounting structure by a mechanism other than the disclosed threaded or snap-coupled connection, thereby removing the need for the elongated passage 626/726. Further, the disclosed spout structures may extend at an angle from hte respective base other than that depicted (e.g., perpendicular to upper wall 625/725). In another alternative embodiment, a cap may be formed that integrated the inner spout portion. Moreover, while the present invention works best with the pinhole membrane valve described herein, it may be possible to replace the pinhole membrane structure with another valve structure that, when combined in series with a baffle, produces at least some of the beneficial characteristics described herein. Therefore, the invention is limited only by the following claims. 

1. A flow control structure comprising: a tube-like spout having a first end and a second end, the spout defining a fluid flow channel extending from the first end to the second end of the spout, the flow channel having a first width; a membrane connected to the spout across the flow channel and positioned adjacent to the first end; and a baffle located in the flow channel and spaced from the membrane such that a first flow channel region is defined between a first side of the baffle and the membrane, and a second flow channel region is located on a second side of the baffle, wherein the membrane defines a plurality of normally-closed pinholes, and wherein the baffle defines an opening communicating between the first and second flow channel regions, said opening having a second width that is smaller than the first width of the flow channel.
 2. The flow control structure according to claim 1, wherein the normally-closed pinholes are formed such that when the membrane is subjected to a relatively low pressure differential and the membrane remains undeformed, the plurality of pinholes remain closed to prevent fluid flow between the fluid flow channel and the external region through the membrane, and when the membrane is deformed in response to an applied relatively high pressure differential, the plurality of pinholes open to facilitate fluid flow through the membrane.
 3. The flow control structure according to claim 1, wherein the spout defines a central axis, wherein the membrane is substantially flat and arranged perpendicular to the central axis, and wherein the baffle parallel to the membrane, and the opening is aligned with the central axis.
 4. The flow control structure according to claim 1, wherein the spout and the baffle respectively have a greater rigidity than the membrane such that, when an applied pressure differential is generated between the fluid flow channel and the external region, the membrane undergoes a greater deformation than the spout and the baffle.
 5. The flow control structure according to claim 4, wherein the membrane and at least an outer spout portion are integrally connected and comprise at least one of silicone, a thermoplastic elastomer, and soft rubber.
 6. The flow control structure according to claim 4, wherein the baffle is integrally connected to an inside surface of the spout.
 7. The flow control structure according to claim 1, further comprising: a first member including an tube-like outer spout portion and said membrane integrally connected to an end of the outer spout portion; and a second member including an tube-like inner spout portion defining said flow channel, wherein said baffle is integrally connected to an inside surface of the inner spout portion, wherein the outer spout portion is mounted over the inner spout portion such that the membrane is positioned adjacent to a first end of the inner spout portion.
 8. A non-spill beverage container comprising: a container body defining a beverage storage chamber and an opening; and a flow control structure mounted over the opening, the flow control structure including: a tube-like spout having a first end and a second end, the spout defining a fluid flow channel extending from the first end to the second end of the spout, the flow channel having a first width; a membrane connected to the first end of the spout such that the membrane extends across the flow channel; and a baffle located in the flow channel and spaced from the membrane such that a first flow channel region is defined between a first side of the baffle and the membrane, and a second flow channel region is located on a second side of the baffle and communicates with the beverage storage chamber through the opening in the container body, wherein the membrane defines a plurality of normally-closed pinholes, and wherein the baffle defines an opening communicating between the first and second flow channel regions, said opening having a second width that is smaller than the first width of the flow channel.
 9. The non-spill beverage container according to claim 8, wherein the normally-closed pinholes are formed such that when the membrane is subjected to a relatively low pressure differential and the membrane remains undeformed, the plurality of pinholes remain closed to prevent fluid flow between the fluid flow channel and the external region through the membrane, and when the membrane is deformed in response to an applied relatively high pressure differential, the plurality of pinholes open to facilitate fluid flow through the membrane.
 10. The non-spill beverage container according to claim 8, wherein the spout defines a central axis, wherein the membrane is substantially flat and arranged perpendicular to the central axis, and wherein the baffle parallel to the membrane, and the opening is aligned with the central axis.
 11. The non-spill beverage container according to claim 8, wherein the spout and the baffle respectively have a greater rigidity than the membrane such that, when an applied pressure differential is generated between the fluid flow channel and the external region, the membrane undergoes a greater deformation than the spout and the baffle.
 12. The non-spill beverage container according to claim 11, wherein the membrane and at least an outer spout portion are integrally connected and comprise at least one of silicone, a thermoplastic elastomer, and soft rubber.
 13. The non-spill beverage container according to claim 11, wherein the baffle is integrally connected to an inside surface of the spout.
 14. The non-spill beverage container according to claim 8, further comprising: a first member including an tube-like outer spout portion and said membrane integrally connected to an end of the outer spout portion; and a second member including an tube-like inner spout portion defining said flow channel, wherein said baffle is integrally connected to an inside surface of the inner spout portion, wherein the outer spout portion is mounted over the inner spout portion such that the membrane is positioned adjacent to a first end of the inner spout portion.
 15. The non-spill beverage container according to claim 14, further comprising a cap mounted over the opening defined by the container body, the cap including an upper wall, wherein the flow control member is mounted on the cap such that the spout extends from the upper wall.
 16. The non-spill beverage container according to claim 15, wherein the cap includes a mounting structure integrally connected to a bottom surface of the upper wall, and the upper wall defines an outlet passage, and wherein the second member further comprises a first base arranged such that the inner spout portion extends from the first base and the flow channel extends through an opening defined in the first base, and wherein the second member is connected to the cap such that the first base is removably attached to the mounting structure and the spout extends through the outlet passage.
 17. The non-spill beverage container according to claim 15, wherein the first member further comprises a second base arranged such that the outer spout portion extends from the second base, and wherein the second member is attached to the mounting structure such that the second base is pressed between the first base and the upper wall of the cap.
 18. The non-spill beverage container according to claim 15, wherein the mounting structure comprises a cylindrical wall and includes threads formed on an inside surface of the cylindrical wall, and wherein the first base of the second member is a disk-shaped structure that includes threads formed on a peripheral edge of the disk-shaped structure that are operably engaged with the threads of the mounting structure.
 19. The non-spill beverage container according to claim 15, wherein the mounting structure comprises a cylindrical wall and includes a lip structure formed on an inside surface of the cylindrical wall, and wherein the first base of the second member is a disk-shaped structure shaped such that a peripheral edge of the disk-shaped structure is snap-coupled the lip of the mounting structure.
 20. A non-spill beverage container comprising: a container body defining a beverage storage chamber and an opening; and a flow control structure mounted over the opening, the flow control structure including: a tube-like spout having a first end and a second end, the spout defining a fluid flow channel extending from the first end to the second end of the spout, the flow channel having a first width; a valve structure connected to the first end of the spout such that the valve structure is located in the flow channel; and means located in the flow channel between the beverage storage chamber and the valve structure for limiting dynamic fluid pressure applied to the valve structure, said means including at least one opening having a second width that is smaller than the first width of the flow channel. 